Among sensors corresponding to the five human senses (sight, hearing, touch, taste, and smell), sensors associated with sight, hearing, and touch, which utilize physical stimuli, have been put to practical use and have come to be used, for example, in mobile devices. However, there has been little progress in providing such mobile devices with sensors associated with taste or smell. Such lack of technical progress may be attributable to a lack of development of a small sensor element that can function as an odor sensor.
As one example, an odor sensor may be composed of a semiconductor gas sensor. However, a typical size of such a semiconductor sensor may be at least about 1 cm, which may reduce its usefulness in a small device. Furthermore, considerable electric power may be required to power a semiconductor gas sensor. Due to its size, this type of odor sensor may be applicable for use in stationary devices, but may not be suitable for use in mobile devices such as cell phones that are powered by batteries.
It is therefore clear that a need exists for a device, system, and method for detecting odorants, capable of being housed in a small portable device.